The unexpected rise of Rick Santorum in the Republican presidential field has provoked more than a few questions about how to respond to assertions that seem to test the limits of both democracy and truth.

For me, one of the most interesting questions bears directly upon my own responsibilities as president of a college. Under what circumstances and to what extent should a college or university president speak directly to political issues and even speak publicly on particular political candidacies?

The rule of thumb has for quite some time been that on such matters presidents had best remain silent. One of the chief jobs of a college leader is to raise money from alumni and other constituencies.

The political views of those groups are likely to be diverse, and silence is therefore preferable to the risk of alienating or aggravating any significant group of potential donors. Fiduciary responsibility requires political restraint.

More important (or at least more noble) is the argument about the preservation of academic freedom on a campus. College and universities should be places where all civil and reasonable views on important issues can be expressed and debated, and a president who takes a public stand on too many of these issues risks stifling debate.

As usual, Bill Bowen, former president of both Princeton University and the Andrew Mellon Foundation, put this best: "The university should be the home of the critic, welcoming and respectful of every point of view; it cannot serve this critically important function if it becomes the critic itself, coming down on one side or another of controversial issues."

To the extent that the president, appropriately or not, is often seen as the personal embodiment of the institution, a politicized presidency risks creating an unhealthily politicized college.

By and large I am a firm believer in the soundness of both of these arguments. But the Santorum candidacy, in my view, provokes the question of whether there are limits to their validity -- that is, is there a set of circumstances under which the responsibility to speak out trumps the responsibility to remain publicly neutral or silent?

I believe the answer to that question is yes, and I believe the circumstances are these: When a policy or an argument or a political platform -- or a candidate -- is antithetical or threatening to the fundamental educational mission of the institution, then in my view it is the responsibility of the president to say so publicly.

Put another way, silence in the face of such threats is a failure of leadership.

The next question to be asked is whether Santorum -- or if one prefers to be less personal, let us say the set of views articulated by Santorum, perhaps imagined collectively as Santorumness or Santorumosity -- qualifies as such a threat.

Let me choose two examples of recent Santorum statements that I believe suggest strongly that this is so. In a well-documented speech in Steubenville, Ohio, this man who would be president asserted that global-warming claims were based on "phony studies" and that climate science was in fact only "political science."

"When it comes to the management of the earth, they"--I'm not sure if this refers to all Democrats, all climate scientists, or all those who believe in evidence-- "are the anti-science ones. We are the ones who stand for science, and technology."

Could there be any more direct threat than this to the very foundations of education: the ability to formulate arguments based on evidence, to use language with precision, to think critically and analytically?

This is not first and foremost about climate change; it is about the responsible and appropriate use of words, facts and ideas. Even those who challenge the findings of climate science should be able to acknowledge that its practitioners are scientists.

To concede that Santorum's remarks are within the bounds of the appropriate is to concede that our work as educators is pretty much meaningless.

One more (though there are so many from which to choose): In an interview several days ago with Glenn Beck, Santorum observed, "I understand why Barack Obama wants to send every kid to college, because of their indoctrination mills, absolutely. ... The indoctrination that is going on at the university level is a harm to our country."

He has since repeated this claim in other contexts.

It is not much of a stretch, I would submit, to see the claims that (1) wanting to see more students attend college is "elitist" and bad for our country and (2) colleges are merely indoctrination mills, as ones with which a college president should publicly disagree, and that a presidential candidate who makes such claims is at least as much a threat to our collective mission as any law or court ruling.

So with all due respect to my responsibilities as a fundraiser and as a guardian of open discourse on my campus, I am prepared to make the case that stating publicly that I am appalled by the views of Rick Santorum is not only my right but my responsibility.

I am appalled by the views of Rick Santorum.

Now excuse me while I go check on the water flow in the indoctrination mill on the northeast corner of the Macalester campus.